1. Field of Invention
The present invention relates generally to an apparatus and method for encoding identifiers on products and materials.
2. Brief Description of the Prior Art
Hundreds of millions of dollars are lost each year in the United States owing to the theft of household goods. A significant problem associated with return of stolen goods is identifying the rightful owner of the stolen good. For example, more than one brand X television is reported stolen in New York City each day.
In general, persons seeking return of goods stolen from their possession have to prove that particular goods belong to them and not to some other victim of a theft. Heretofore, the best way of correlating a particular item with ownership was to keep a record of the serial number which is often engraved on, or attached to, the surface of a product.
The method of attaching a serial number plate to, or engraving a serial number on, a consumer good is well known in the art. Such method is exemplified in U.S. Pat. No. 4,936,608, in which industrial products are marked by “burning-in” alphanumeric numbers by means of a laser.
Promotional literature which comes with a new consumer products not infrequently includes a card with the serial number imprinted thereon. Recordation of ownership may be made by mailing the card into the manufacturer. Commonly, however, many of these cards are never returned by the purchaser and are subsequently discarded.
One significant problem associated with visible serial numbers, whether on a plate or engraved on the product, is that they provide for visual inspection of the serial number not only by the consumer of the good, but also by the thief. Thieves often eradicate visible serial numbers on stolen goods. Once the serial number has been removed, it is often impossible to correlate the true owner with the stolen item.
In order to prevent thieves from eradicating all serial number identifications from a product, it has been proposed that the serial number be printed on the product with invisible ink. For example, in U.S. Pat. No. 5,194,289, ultraviolet dyes are employed to imprint identification numbers. Similarly, in U.S. Pat. No. 5,360,628 an infra-red absorbing dye. IR 140 (5,5′-dichloro-11-diphenylamino-3,3′-diethyl-10,12-ethylenethiatricarbocyanine perchlorate (CAS53655-17-7)) and invisible electrically conductive inks are disclosed. Others have proposed using biologic material for the concealed, unique identification of a product. U.S. Pat. No. 5,194,289 utilizes biologic markers, such as amino acids, proteins, and nucleic acids to identify an object. U.S. Pat. No. 4,880,750 discloses the use of individual-specific antibodies in an ink for identification of security documents. U.S. Pat. No. 4,441,943 uses synthetic polypeptides for labeling explosives.
Invisible ink or material on the surface of the product also presents problems. Although more difficult for a thief to discern, such printing is usually easily removable from the surface of the product. Further, it is often difficult for law enforcement officials to determine where the invisible marking is located.
Both engraving of a serial number or the attachment of a serial number plate onto a product and the imprinting the surface of the product with invisible material provides for no direct mechanism of identifying the particular product with the purchaser of the product. Heretofore, as set forth above, the conventional means by which a particular product was identified with a purchaser was by means of consumer or retailer registration of ownership with the manufacturer by mailing in the serial number identification card.
In order to resolve these problems, it has been proposed in U.S. Pat. No. 5,083,814 that valuable personal articles be marked with an invisible ink at random locations on an article, such location being chosen by computer programmed to chose one of several hundred possible marking sites, and that the installer of the security marking record and input data pertaining to the ownership of the article in a limited-access central database. While this system provides for protection of the initial purchaser of a valuable good, it does not provide a method for registering subsequent purchasers, nor does it provide a method of automatically registering the purchaser of every day consumer goods. Further, while making it more difficult for a thief to discern the serial number, such technique does not prevent the thief from “filing-off” the serial number once it is discovered by means of an infra-red sensor, etc.
The correlation of a product with the purchaser of that product is also a problem in identifying the perpetrator of a crime. For example, criminals are adept at finding and removing serial numbers engraved on firearms. The discovery of a firearm at a crime scene often provides police with little clue about the perpetrator of the crime. Likewise, heretofore, it has been very difficult for police to correlate the purchaser of ammunition with the slug found in a body. Visibly marking the ammunition with a serial number and correlating the same with a purchaser have been proposed. Again the problem with such a system is that the visible serial number is easily removed by a criminal disposed to do such.